Witnesses say Bahraini riot police have chased anti-government protesters out of the center of the island kingdom's capital.
The scuffles Wednesday came a day after authorities denied the country's main Shiite-backed opposition party, Al Wefaq, permission to hold protests in central Manama.
Witnesses say hundreds of protesters were scattered throughout the old city and diplomatic area, and police used stun grenades to disperse some of them.
Bahrain's majority Shiites have been the driving force behind widespread protests inspired by the Arab Spring uprisings over the past year.
Wednesday's protests erupted a day before Bahrain hosts an air show that runs through Saturday.